In this version, the cap screws on the barrel rather than the section. When the cap screws in fully, the pattern on the cap should line up with the pattern on the section.

Note: The section on this model is fragile, specifically the threads that screw into the barrel. Be gentle when screwing the section on and off.

I have an updated version that fixes the fragile section at https://www.printables.com/model/369588-fountain-pen-version-25

Layer Height: 0.2

Infill: 20%

No supports required.